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Message-ID: <28f69c51-0778-56f3-62fd-172b60a039d8@loongson.cn>
Date:   Fri, 13 May 2022 09:59:07 +0800
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Subject: Re: [PATCH v3] mm/khugepaged: sched to numa node when collapse huge
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To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Yang Shi <shy828301@gmail.com>
References: <20220317065024.2635069-1-maobibo@loongson.cn>
 <3a441789-b3e4-236e-2e44-e7a1c7258a94@redhat.com>
 <YmrB/7ehG2kj2RMn@xz-m1.local>
 <20220512173620.2f5175c7a321e6ccea6e58e9@linux-foundation.org>
 <8c1fc6d4-7d3a-85dd-ebd9-fc8e221f1878@loongson.cn>
 <69c4f018-2012-8af5-569b-289d2a8a80f5@loongson.cn>
 <20220512184908.0852e1efcb6fd78aea52b557@linux-foundation.org>
From:   maobibo <maobibo@loongson.cn>
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在 2022/5/13 09:49, Andrew Morton 写道:
> On Fri, 13 May 2022 09:29:07 +0800 maobibo <maobibo@loongson.cn> wrote:
> 
>>
>>
>>>> and/or changelogging.
>>> Sorry for the late response, the mail is filtered and I did not notice that. The result is not so obvious after bandwidth is improved between nodes, it is only about 1% improvement for specint2006 for 32 core on my box.
>>>
>>> Now I do not see negative effective about this patch unless user wants to keep some cores separated from khugepaged daemon process.
>>
>> Can we provide an extra parameter to let khugepaged daemon scheduling binded to node or freely? If can, I will provide updated patch.
> 
> It has always surprised me that we have a single khugepaged thread.  If
> we had a thread per node, you'd be all fixed up, yes?
yes, it will solve this issue if there is a thread per node, also it can speed up huge page scanning. It should be useful for some workloads in short time like specint.
> 
> Ditto ksmd.